cfg80211: update comment about WIPHY_FLAG_CUSTOM_REGULATORY

Commit a2f73b6c5db3c ("cfg80211: move regulatory flags to their own variable")
renamed WIPHY_FLAG_CUSTOM_REGULATORY to REGULATORY_CUSTOM_REG, but missed to
update one comment.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -3609,7 +3609,7 @@ int regulatory_hint(struct wiphy *wiphy, const char *alpha2);
  * default channel settings will be disregarded. If no rule is found for a
  * channel on the regulatory domain the channel will be disabled.
  * Drivers using this for a wiphy should also set the wiphy flag
- * WIPHY_FLAG_CUSTOM_REGULATORY or cfg80211 will set it for the wiphy
+ * REGULATORY_CUSTOM_REG or cfg80211 will set it for the wiphy
  * that called this helper.
  */
 void wiphy_apply_custom_regulatory(struct wiphy *wiphy,